Wireless communication systems are widely deployed to provide various types of communication content, including voice, video, packet data, messaging, and broadcast, among many others. Wireless communication systems (e.g., multiple-access networks that can share available network resources to support multiple users) have developed through various generations, including a first-generation analog wireless phone service (1G), a second-generation (2G) digital wireless phone service (including interim 2.5G and 2.75G networks) and third-generation (3G) and fourth-generation (4G) high speed data/Internet-capable wireless services. There are presently many different wireless communication systems in use, including Cellular and Personal Communications Service (PCS) systems. Example cellular systems include the cellular Analog Advanced Mobile Phone System (AMPS), digital cellular systems based on Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Orthogonal FDMA (OFDMA), Single-Carrier FDMA (SC-FDMA), the Global System for Mobile access (GSM) TDMA variation, and newer hybrid digital communication systems that use both TDMA and CDMA technologies. More recently, Long Term Evolution (LTE) has been developed as a wireless communication protocol for wireless communication of high-speed data for mobile phones and other data terminals. LTE is based on GSM, and includes contributions from various GSM-related protocols (e.g., Enhanced Data rates for GSM Evolution (EDGE)) and Universal Mobile Telecommunications System (UMTS) protocols (e.g., High-Speed Packet Access (HSPA)).
In general, a wireless communication network may include various base stations (also referred to as evolved node Bs, eNBs, or access nodes) that can support communication for a user equipment (UE). In a WAN, a UE typically communicates via uplink/downlink channels between the UE and a base station to thereby communicate with the base station. However, if two or more UEs are in within sufficient proximity to one another, the UEs may be enabled to communicate directly, that is, without communicating through any base station. A UE may therefore support direct peer-to-peer (P2P) or device-to-device (D2D) communication with one or more other UEs.
For example, LTE-Direct (LTE-D, sometimes also referred to as “LTE-Advanced”) is a proposed 3GPP (Release 12) D2D solution for proximate discovery. LTE-D dispenses with location tracking and network calls by directly monitoring for services on other LTE-Direct devices within a large range (˜500 m, line of sight). As such, among other advantages, LTE-D can directly monitor for services on other LTE-D devices in a synchronous system and concurrently detect many services in proximity in a continuous and battery efficient manner. In another example, the Wi-Fi Alliance Peer-to-Peer (P2P) Specification, also known as “Wi-Fi Direct” (WFD), supports pre-association service discovery among peer wireless devices. The WFD protocol enables a client wireless device or station (STA) to query peer STAs within Wi-Fi range to determine what services, if any, are available on the peer STAs. Determining the services that peer STAs provide typically involves a device discovery phase and a service discovery phase. During the device discovery phase, a client STA (e.g., a STA requesting a particular P2P service) determines the identity and/or availability associated with other STAs within Wi-Fi communication range via “scanning” the three social channels (e.g., channels 1, 6, and 11 in the 2.4 GHz band) to detect incoming beacon frames and/or broadcasting probe request frames to any client STAs that may be listening on the social channels. Thereafter, during the service discovery phase, the client STA queries any available peer STAs that may have been discovered during the device discovery phase about the services that the available peer STAs provide. For example, the client STA typically transmits one or more service discovery requests to each peer STA that supports the service discovery operation, one at a time, until the client STA identifies a suitable peer STA that provides the requested service.
Accordingly, service discovery messaging and signaling is the bedrock for many wireless use cases and application platforms, which may include mirroring, screen sharing, streaming video, streaming audio, remote video/graphics rendition, remote audio rendition, remote sensing, remote control, and file transfers, among many others. In general, service discovery messages and signaling can be used to support announcements and inquiries, composition and mediation, control and presentation, and can further be extended to group management and addressing control, quality of service (QoS) and/or quality of experience (QoE) management, and various other wireless use cases. In any particular wireless application and/or use case where service discovery messaging is used to support out-of-band P2P and/or D2D communication, a wireless application processing datapath can include many ad-hoc devices that will often have unequal capabilities, processing densities, storage capacities, connection and power performance profiles, etc. Furthermore, any device can operate autonomously and without awareness of other devices, whereby operational dependencies and required collaboration among different devices are typically validated and resolved per-application and/or use case. Hence, a collaborative and distributed (unstructured) service discovery framework typically requires regular service discovery messaging, which may require that each peer device maintain one or more components in a wireless application datapath in an always-on state (e.g., a host bridge, interconnect and system memory, host application processor and high-level operating system typically used to process service discovery messages and signaling).
As such, the need to process and respond to occasional service discovery messages may cause components in the wireless application datapath to stay in an always-on state, which can consume substantial power even though service discovery messages typically have small payloads (e.g., a few bytes). Furthermore, because each client STA typically has no knowledge about whether or not the service(s) that other previously discovered peer STAs provide have changed unless the service discovery (and device discovery) operations are periodically repeated with each peer STA, establishing and maintaining out-of-band P2P and/or D2D connections can consume substantial time and resources, which may be especially problematic in battery-powered electronic devices.